Microwave-assisted synthesis, crystal structures, and in vitro antibacterial studies of manganese(III) and iron(III) complexes derived from N,N′-1,2-ethylene-bis(3-ethoxysalicylideneimine)

The syntheses of a mononuclear manganese(III) complex [MnL (dca)(OH2)] and a mononuclear iron(III) complex [FeLL]ClO4 (H2L = N,N-1,2-ethylene-bis(3-ethoxysalicylideneimine); L = 2- [(2-ammonioethylimino)methyl]-6-ethoxyphenolate; dca=dicyana mide), by a one-step sequence from the reaction of 3-ethox ysalicylaldehyde, 1,2-diaminoethane, dca, and metal salts under microwave irradiation are described. The newly prepared complexes were characterized by a combination of elemental analyses and IR spectra. Their structures were determined by single-crystal X-ray crystallography. The metal centers in the complexes are in octahedral coordination. The crystals of the complexes are stabilized by hydrogen bonds. In order to evaluate the biological activity of the ligand and to evaluate the role of manganese and iron ions on biological activity, the free ligands and the complexes have been studied in vitro antibacterial against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa.